Aspartame, L-aspartyl-L-phenylalanine methyl ester, is a known artificial sweetener, U.S. Pat. No. 3,492,131. Its use in chewing gum formulations is restricted, however, due to its instability when present in such formulations. Thus, aspartame containing chewing gum formulations are known to lose their sweetness with the passage of time (U.S. Pat. Nos. 4,122,195 and 4,139,639); thereby severely limiting the shelf life of an aspartame sweetened chewing gum. U.S. Pat. Nos. 4,122,195 and 4,139,639 attempt to solve this inherent instability problem by fixing aspartame in various encapsulating compositions prior to its incorporation in a chewing gum formulation.
The present invention solves the instability problem by coating aspartame onto the surface of the chewing gum piece. The advantages of the present invention over the tedious methods taught by the prior art will be apparent to those skilled in the art.